1. Field of the Invention
In medical technology a mechanism for closing off a tubular vessel in the body is called a clamp.
This invention relates to a clamp that is applied to a limb for the purpose of closing a blood vessel or blood vessels of an arm or leg that are open to the surface.
More specifically, this invention relates to a clamp that encircles a limb and applies local pressure to blood vessels that are open to the surface for the purpose of effecting a stoppage of bleeding by the method commonly referred to as direct pressure.
Still more specifically this invention relates to the clamp described above wherein the clamp is particularly well suited for applications involving the closing of blood vessels of dialysis patients after the needles have been removed from the blood vessels of the patient.
Clamps that encircle a limb and apply direct pressure to blood vessels should do so while not shutting off circulation of blood to the ends of the extremity to which the clamp is applied.
In dialysis, tubes are inserted into a vein and an artery either directly into the blood vessels or by way of a surgical implant and blood is circulated from the artery and through a dialysis machine for the purpose of cleansing the blood after which the blood is returned to a vein.
The process of dialysis takes several hours and often needs to be repeated several times a week. Because of the duration of the dialysis, and the size of the needle used, the opening through the skin can become enlarged and difficult to close and may require an extended period of time before direct pressure can affect a closure of the blood vessel. The patient who has been attached to a dialysis machine for several hours is understandably in need of moving the limb to which the clamp is applied. A successful clamp must be able to accommodate to a limited amount of movement of the limb without moving from position over the opening or openings or losing its clamping pressure.
2. Description of the Related Art
Prior art clamps of the type contemplated by this invention are deficient in one or more of the following attributes.
Because of the number of times a clamp is employed on a dialysis patient the disposal of the clamp after a single use is not economically preferred. Therefore a successful clamp must be made of durable material that can repeatedly be cleaned and/or disinfected.
Because bleeding is often present before the clamping becomes effective, the successful clamp must be made of a smooth nonabsorbent material and be free of recesses into which blood or other contaminants may enter and be difficult to remove.
Because the patient in moving a limb will cause the limb to expand or contract, the band that encircles the arm must be accommodating to the expansion or contraction of the limb without losing position or pressure over the skin openings.
Because the direct pressure method in order to be effective must hold the sides of the opening in position and in alignment with each other until the closure knits shut, it is critical that the opening not be distorted during closure. Distortion of the opening might cause stresses in the newly closed vessel and result in reopening of the vessel after the pressure is removed.
Because the pressure is to be applied locally and frequently and for significant periods of time, it is critical that the perimeter of the pressure-applying portion of the clamp and the band that secures it be smooth and non-irritating, thereby avoiding damage to the skin or the blood vessels of the patient.
The most closely related art is found to have adjustable bands that encircle a limb and generally provide a positioning or holding function for catheters and intravenous needles. The prior art can be said to have one or more attributes in common with the instant invention, but none of the prior art provides the same means operating in the same mode to achieve the same ends as that of the instant invention.
U.S. Pat. No. 5,269,803 to Geary teaches a disposable one-piece hemostasis pressure clamp having a central channel defined by a pair of cheeks and a ridge formation formed of non-elastic plastic.
U.S. Pat. No. 3,059,645 to Hasbrouck et al teaches a unitary adjustable clamp for holding intravenous needles wherein the clamp is provided with projections that are engageable with openings spaced apart along a strap that encircles a part of the anatomy of the user.
U.S. Pat. No. 6,074,368 to Wright teaches a catheter holder that has a disk shape.
A direct pressure clamp having a pressure applying head formed integral with a limb encircling band and formed of a firm elastomeric material wherein the head is provided with a broad upper gripping plate and an integral smaller pressure applying plate and an upper surface of the gripping plate is provided with at least one projection that is engageable with elastically deformable orifices defined by the band at spaced apart intervals along the limb encircling band.